Abstract:

An apparatus and method is disclosed that provides a means for mounting a
separate optical element, such as a gonio lens, to a hand-held eye
imaging device. In this way, the doctor only needs to use one hand to
hold the imaging apparatus while the other hand can be freed to open the
patient eye lid and also maintain a safe relative distance of the gonio
lens with respect to the patient's eye. The gonio lens and adaptor can
each or both be made disposable and also mechanically switchable relative
to each other as well as relative to the handheld eye imaging device so
that different portions of the patient eye can be imaged sequentially
without the need to rotate the hand held eye imaging device.

Claims:

2. The means of claim 1 wherein the separate optical element is a gonio
lens.

3. The means of claim 1 wherein the hand held eye imaging device is EyeCam
or RetCam eye imaging system.(other claim points)The adaptor can be
snapped onto the body of the handheld eye image device without the need
for a tool.The gonio lens and adaptor assembly can be rotated with
respect to the handheld eye imaging deviceThe gonio lens and adaptor
assembly can be snapped into different positions with respect to the
handheld eye imaging device.The gonio lens can be transversally moved off
center with the desired orientation and lock into positions relative to
the adaptor.The gonio lens can be rotated off center with the desired
orientation and lateral displacement, and mechanically locked into
positions relative to the adaptor.The gonio lens can be made disposable
and snapped onto the adaptor.The gonio lens or the gonio lens and the
adaptor assembly can be made disposable.The front portion of the gonio
lens that makes contact with the eye can be made disposable.The gonio
lens or the adaptor or the handheld eye imaging device can have reticle
made within to help align the eye relative to these land marks.The gonio
lens can be designed to have spatially different imaging characteristics
to simultaneously provide clears images of both the anterior and the
posterior of the eye.

[0003]Figure A illustrates the one example of the disclosed means for
mounting a detachable gonio lens onto a handheld eye imaging device.

DESCRIPTION OF EXAMPLE EMBODIMENTS OVERVIEW

[0004]This disclosure describes a means for mounting a separate or
detachable optical element such as an off the shelf (OTS) optical lens or
a gonio lens with mirror facet(s), disposable or non-disposable to a
hand-held eye imaging device with the help of a mechanical adaptor. In an
example embodiment, when gonioscopy imaging is being conducted, the
doctor only needs to use one hand to hold the imaging apparatus, while
the other hand can be freed to open the patient eye lid and/or to
maintain a safe distance between the gonio lens and the patient's eye.
The adaptor can be made disposable and also mechanically switchable so
that the detachable optical element (such as a gonio lens) can be moved
to different positions relative to the handheld eye imaging device to
enable different portions of the eye to be sequentially imaged without
the need to rotate the handheld eye imaging device which may have been
ergonomically designed for hand holding with a certain orientation.

[0005]Reference will now be made in detail to various embodiments of the
invention. Examples of these embodiments are illustrated in the
accompanying drawings. While the invention will be described in
conjunction with these embodiments, it will be understood that it is not
intended to limit the invention to any embodiment. On the contrary, it is
intended to cover alternatives, modifications, and equivalents as may be
included within the spirit and scope of the invention as defined by the
appended claims. In the following description, numerous specific details
are set forth in order to provide a thorough understanding of the various
embodiments. However, the present invention may be practiced without some
or all of these specific details. In other instances, well known process
operations have not been described in detail in order not to
unnecessarily obscure the present invention. Further, each appearance of
the phrase an "example embodiment" at various places in the specification
does not necessarily refer to the same example embodiment.

[0006]Traditional gonioscopy is usually conducted using a slit lamp with
the patient placing his/her chin on a chin rest and the doctor holding a
gonio lens against the eye of the patient while looking through the slit
lamp to directly observe the angle region of the patient's eye. The gonio
lens can have one, two three or four mirrored facets to direct
illumination and imaging light to the angle region of the anterior
chamber of the patient eye. Usually, such a slit lamp based gonioscopy
imaging requires the use of the doctor's two hands. The doctor needs to
use one hand to hold the handle of the gonio lens and maybe laterally
translate the gonio lens relative to the patient eye in order to see a
large area of one section of the anterior angle, while his/her other hand
needs to be used to open or hold the patient's eye lid or to adjust the
optics of the slit lamp.

[0007]When a handheld eye imaging system such as the RetCam system is used
for anterior chamber angle imaging, there are two possible approaches
that can be taken. The RetCam system is manufactured by the assignee of
the present application and includes a light weight video camera in a
plastic or metal holder that facilitates the connection of changeable
lenses. Details of the RetCam system are available Claritymsi website
with the extension .com/downloads/RetCam.pdf. The first approach is to
use a wide angle RetCam lens piece to directly image the anterior chamber
angle region with the handheld assembly substantially tilted with respect
to the optical axis of the eye and in doing so, there is a need for an
optical coupling gel to fill the relatively large wedge gap between the
patient eye and the front lens surface of the handheld assembly. A
problem with this approach is that the optical coupling gel tends to
flatten if the patient is lying down on his/her back or the gel tend to
drip off if the patient is sitting upright. A second approach is to place
a gonio lens between the patient eye and the handheld eye imaging device
so that the handheld eye imaging device can be held relatively normally
with respect to the eye to leave only a small gap to be either filled by
the eye tear or a small amount of optical coupling gel which can be thin
and easy to wipe off afterwards. However, with this second alternative
approach, there is a need to mechanically attach the gonio lens to the
handheld assembly as otherwise, the doctor has to use one hand to hold
the gonio lens and the other hand to hold the handheld imaging device,
which will make it difficult for the doctor to properly control a safe
distance between the eye, the gonio lens and the hand held imaging
device.

[0008]Various example embodiment, including apparatuses and methods are
disclosed that enables a handheld eye imaging device such as the RetCam
system to view an image (anterior or posterior of the eye) through a
separate optical element (contact or non-contact gonio lens, Iridectomy
lens, for examples) without the need to hold both the separate optical
element and the eye imaging system with two hands. In the case of a gonio
lens, for example, depending on the number of mirror facets made on the
gonio lens, there may be a need to laterally translate the gonio lens
from one side to the other side with respect to the handheld eye imaging
device such as a slit lamp or fundus camera so that the anterior chamber
angle image can be moved to the central region of the field of view of
the image sensor. On the other hand, if there is only one mirrored facet
on the gonio lens, there may be a need to rotate the gonio lens
off-center into 4 quadrant positions relative to the handheld eye imaging
device in order to capture 4 quadrant section images of the anterior
chamber angle of the patient eye. Note that the off center translation of
the gonio lens relative to the handheld eye imaging device, such as the
RetCam imaging system, will not only move the anterior chamber angle
image towards the center of the field of view but also produce a larger
and better view of the angle region of the patient's eye. The presently
invented apparatuses and methods can mechanically hold the separate
optical element to be combined with the handheld imaging system at the
correct spatial requirements to optimize the anatomical image onto the
system's image sensor. This example embodiment could also allow the
change in orientation of the separate optical element to that of the
patient/system, by either a lateral, rotational or angular
movement/displacement. This example embodiment could also provide an
optical coupler between the handheld imaging system and separate optical
element, while at the same time provide the desired/optimal angular,
rotational, or spatial arrangement and orientations. Another aspect of
the invention is to make either the separate optical element such as the
gonio lens, or the adaptor, or both the separate optical element and the
adaptor, disposable. In this way, cross contamination among different
patients can be minimized. Still another aspect of the present invention
is that the separate optical element and the adaptor can be snapped or
attached to the handheld imaging device without the need for other tools.

[0009]This example embodiment optimizes the viewing and digital imaging
capability of existing products, while at the same time providing a more
consistent, controlled, and easier implementation/use of acquiring
digital images. In addition, this device can facilitate better digital
documentation of an eye's anatomy, whereas most lenses require a two-hand
operation with analog imaging devices.

[0010]This example embodiment is an improvement to existing methods and
products, which combines two separate devices, one that can acquire an
image with one that provides direct analog (human) visualization over a
greater area of anatomy. The combination of the two, results in the
ability to acquire high-quality digital images over a greater area of
anatomy.

[0011]One method of attachment for the gonio adapter that may be
implemented is by making a groove around the periphery of the RetCam lens
piece. This would provide the rotational adjustment and position the
separate lens and adaptor assembly at the proper distance with the proper
orientation relative to the RetCam lens piece. There may be positioning
detents machined into this groove so that the gonio lens and the adaptor
assembly can lock into two or more positions 90 or 180 degrees apart from
each one another. For a one mirror faceted gonio lens, four positions
separated 90 degrees apart can be selected. For a two mirror faceted
gonio lens, two positions separated by 180 degrees can be selected to
enable the gonio lens to achieve a lateral translation relative to the
RetCam lens piece. Meanwhile, 4 or more positions separated by any
orientation angles can also be selected to enable the handheld eye
imaging device to capture multiple images of the eye. The separate
optical element can also be mounted onto two rods and thus can slide
along those rods, providing the required off center translation of the
gonio lens with respect to the RetCam lens piece. In the illustration as
shown in Figure A, the machined groove is not shown on the RetCam lens
body, it is held in place with setscrews for prototyping ease. However,
it is preferred that the attachment of this adapter to the RetCam lens
piece is without the use of tools. The adapter may snap into a groove
around the RetCam lens housing. The use of a groove will allow the gonio
lens to be rotated about the RetCam lens piece with ease.

[0012]A second alternate method is to attach the gonio lens and the
adaptor assembly via a series of slots that runs along the length of the
RetCam lens piece. There can, for example, be 4 of these slots, separated
90 degrees apart, around the body of the RetCam lens piece. The gonio
lens mounted on an adaptor as an assembly can slide into these slots and
there can be a detent at the end of each slot to lock the adaptor into
place. Rotation of the gonio lens would be accomplished by pulling it off
the RetCam lens piece, rotating the assembly 90 degrees, and re-inserting
it into the slots.

[0013]A third example method to rotate the gonio is to mount a single
faceted or mirrored gonio lens on a rotating ring where the lens and the
ring do not rotate in relation to each other. The preferred viewing axis,
and offset, of the gonio is aligned to the optical axis of the RetCam, or
other lens. There can be four detents, 90 degrees apart, to position the
gonio lens. Generally, optical components are rotationally symmetric; the
gonio lens can be constructed so that this is not the case. If the gonio
lens outside diameter, or mounting surface, provides the offset, then as
the lens is rotated about its mechanical axis it would provide the
correct views. Another advantage to this is that at different offset, or
angle, the gonio lens can be placed into the same adapter. The lens
provides the correct offset, not the mechanical components.

[0014]An alternate method of translation and rotation is to use three
eccentric ring(s). This would require a groove, either machined into the
RetCam lens piece or attached onto it, as the guide for rotation. Into
this groove are three rings. The middle ring has its outside diameter and
inside diameter off set (eccentric) by 1/2 the amount of travel required
per the desired off center distance for the gonio lens relative to the
center of the RetCam lens piece. Rotation of this middle ring will
provide the translational travel to the gonio lens. The inner ring, outer
ring and the gonio are keyed to rotate together. Rotation of these
elements will provide the two halves or 4 quadrant views required for
examination. The relatively rotatable rings should have detents so that
the gonio lens is aligned at 90 degree steps. An alternate method of
locking the gonio lens into place may be the use of magnets as the
detents. In addition, ring rotating segment can have a toric inner and
outer radius that can permit rotation as well as angular tilt in order to
optimize the view relayed by the gonio optics through the RetCam. An
angular adjustment of the optical axis will facilitate a fine tuning to
improve the view of the individual features of the anterior and most
importantly the various anatomical structures of the angle as well as
views of various implants or post-surgical results for the clinicians
further evaluation.

[0015]Any of the above-mentioned mechanical structures may be machined
into the RetCam lens piece housing at initial manufacture or they may be
retrofitted as an applied ring to the body of the RetCam lens piece
housing. This ring may be mounted by adhesive or mechanically.

[0016]Another method to provide transversal travel of the gonio lens with
respect to the RetCam lens piece is to use parallel arms. There can be
one arm mounted on each side of the gonio lens. These arms, at the other
end, can be fixed to the body of the RetCam lens piece or the adapter
ring. Located at one end, or both ends, would be a detent to lock the
rotation and/or translation of these arms at the point that they have
traveled the correct distance for the required amount of travel for the
gonio lens. This detent snap into place, letting the operator know that
it has traveled the correct distance.

[0017]A variation of the parallel arm travel is to use arms that are not
parallel. The arms would converge at a point in front of the gonio lens.
This would rock the gonio lens as it travels to its two positions,
required an asymmetric lens. The advantage to this is that the front
portion of the adapter can be much smaller than the other designs, with
the exception of the eccentric ring design.

[0018]One preferred embodiment of the present disclosure is that part of
the gonio lens or the gonio lens or the gonio lens and the adapter
assembly be made disposable. There are several ways to make this
implementable. The gonio lens can be a injection molded plastic element
and in such a case, it can be removed from the adaptor and discarded
after each use. The gonio may have a snap-into-place feature that
attaches itself to the adapter. One feature that may be useful for the
gonio lens is the use of a soft front contact cup. The portion of the
gonio lens that actually contacts the eye may be made of some resilient
optical material to improve patient comfort and safety in the case of
sudden eye movement. The contact cup may be a hydrogel, silicone or
similar molded component. The contact cup may be the portion that is
disposable in this system. It may have other mechanical features, gel or
releasable adhesive that would lock it into place. The front portion of
the gonio lens can also be a thin layer of optically transparent coupling
film or a gel/fluid filled bag or simply a gel that can be later wiped
off the eye. This optically transparent layer can be attached to the rest
of the gonio lens through various means such as liquid filled vacuum
suction and this would reduce the cost of the replacement component.
Still another possibility is to make the gonio lens and the adaptor
assembly disposable by, for example, making this whole assembly with
plastic injection molding.

[0019]In order to improve the accuracy and repeatability of the images
captured from the same eye, additional features can be added to overlap
the image taken. For example, when the anterior segment image is
recorded, the position of the pupil and some features on the retina,
possibly the fovea, macula, or the optical nerve head can also be
simultaneously recorded. This information could be overlaid during the
following eye examinations to align the handheld imaging system. While
the overlaid image might be software selected so that the pupil edge and
some high contrast landmarks on the retina surface are viewed, an
alternative can be to have a reticle that may have concentric rings to be
made inside the gonio lens or the adaptor or the RetCam lens piece as
long as the reticle is roughly in a conjugate plane to the image sensor
plane. In this way, the reticle can be used to align the pupil and/or a
landmark on the retina, such as the macula, fovea or optical nerve head,
which may be different for the left eye and right eye. The gonio lens or
the adaptor or the assembly of the two can also be optically designed to
have spatially different imaging properties so that while a certain
portion of the field of view will produce a well focused anterior chamber
angle image, another portion of the field of view will at the same time
produce a well focused fundus or retina image. This aspect of the
invention can be used to align the combined eye imaging apparatus to be
square to the eye and/or to be centered and rotationally positioned
properly before an image is taken. It would also allow the registration
of the images taken at different times to be relatively repeatable. This
repeatability can be more important for a handheld eye imaging device
than a bench top device due to lack of patient support and positioning.

[0020]The presently disclosed apparatus and method can be applied to any
optical imaging system and a separate optical element that can be
attached to the system to enhance the performance of the system. For
examples, the system could be adapted to a microscope's ocular "port";
integrated into a slit-lamp tower; adapted to gonio lenses; the separate
optical element could be integrated into the system's lens; and the
design features of the separate optical element could also be integrated
in the system;

[0021]In addition to optometrist and ophthalmologist practices; the
presently described example embodiments can effectively be applied to
anywhere as long as the visualization of an eye's anatomy is desired.

[0022]The invention has now been described with reference to the example
embodiments. Alternatives and substitutions will now be apparent to
persons of skill in the art. For example, the example embodiments have
been described with reference to the RetCam system but other handheld
video systems can also be utilized. Accordingly, it is not intended to
limit the invention except as provided by the appended claims.